In aqueous systems, particularly industrial water systems such as cooling water systems, the accumulation of deposits on the internal surfaces of the equipment, pipes, and the like may interfere with water flow, accelerate corrosion of metal parts, reduce heat transfer, and lead to other undesirable problems. Such deposits include deposits of scaling salts that form and precipitate under various conditions in the aqueous environment, including the type and amount of anions and cations present, pH, temperature, and the like. A water treatment agent that is active as a threshold inhibitor and/or dispersant for scaling salts, that is effective at low dosage levels, and that is stable under the environmental conditions found in industrial water systems, particularly cooling water systems, is extremely desirable, particularly if such agent is effective as both a threshold inhibitor and dispersant, and is effective for reducing deposit accumulations of various scaling salts.